Luminaire



April 22, 1958 F. c. WINKLER ET AL 2,831,952

LUMINAIRE Filed April 14, 1955 s Sheets-Sheet 1 WITNESSES: INVENTORS f cFrederic C.WinkIer 477744 ggd Nick Stuffer.

ATTORNEY April 1958 F. c. wlNKLER El' AL 2,831,962

LUMINAIRE Filed April 14, 1953 5 Sheets-Sheet z INVENTORS FredericC..winkler and Nick Stuffer.

ATTORN EY Fig.2.

April 22, 1958 F. C. WINKLER ETAL LUMINAIRE 5 Sheets-Sheet 3 Filed April14, 1953 April 22, 1958 F. c. WINKLER ETAL 2,831,952

LUMINAIRE Filed Ap ril 14, 1953 s Sheets-Sheet 4 M3 u "r April 22, 1958F. c. WINKLER ET AL LUMINAIRE 5 Sheets-Sheet 5 Filed April 14, 1953INVENTORS Frederic C.Winkl(:r and Nick Shaffer.

ATTORNEY WITNESSES: x54 WJMZ L 58 LUMINAIRE Frederic C. Winkler,Cleveland, and Nick Stuifer, Lakewood, Ohio, assignors to WestinghouseElectric Corporation, East Pittsburgh, Pa., a corporation ofPennsylvania Application April 14, 1953, Serial No. 348,674

8 Claims. (Cl. 240-9) This invention relates to luminaires generally,and more particularly to elongated luminaires which are adapted for avariety of purposes and arrangements.

The invention as herein illustrated embodies forms of luminaires whichare adapted to be mounted in ceiling recesses; however, certain featuresthereof are equally useful in luminaires recessed in openings other thanin ceilings, and other features are equally useful in luminaires whichare not mounted in recesses.

One problem encountered in recessing luminaires resides in the varietyof openings or ceiling constructions in common use, therefore oneimportant object of this invention is to provide a standard form ofluminaire which is readily adaptable to a variety of buildingconstructions.

While certain details of luminaires used in diflerent types of buildingconstructions necessarily vary in cer- United States Patent tainfeatures thereof, another important object of this invention is toprovide for standard component parts which are particularly constructedto be cooperable with a. number of different types of luminaires.

Luminaires of the type described herein generally have substantiallyinverted U-shaped housings with a shielding device for the open side,which may be either a framed louver assembly or a framed translucentcover assembly. Such housings may be mounted individually with endplates closing the ends of the housing or in continuous rows of housingsmounted in tandem in either parallel or intersecting lines. In the pastsuch arrangements have had objectionable light leakage at the edges ofthe shielding devices, particularly when the housings are aligned sothat a continuous line of shielding devices are arranged in anend-to-end relationship. Another important object of this invention is,therefore, to provide a luminaire construction having novel provisionfor preventing leakage of light around the edges of the shieldingdevices, irrespective of the number employed or the arrangement thereof.

It is also an object of this invention to provide a novel form ofrecessed luminaire housing in the form of a trough having novel meansfor mounting other comr ponents therein, so that all installation workmay be done from the open side of the trough.

Another object of this invention is to provide a recessed luminairehousing of trough shape having a novel end construction which may becooperable with either covering plates or coupling elements so that theend plates and coupling elements may be readily installed from the open1 side of the housing, either before or after the ceiling installation.

Still another object of this invention is to provide a recessed type ofluminaire having an inverted U-shaped housing with novel means forsecuring the housing to a variety of standard support members from theopen side of the housing.

Yet another object of this invention is to provide a recessed type ofluminaire having a trough shaped housing with a novel intermediatereinforcing member which is readily removable from the underside of thehousing to permit the mounting or replacement of lamps in the luminaire,and which will not have any objectionable light leakage around itsedges.

A more specific object of this invention is to provide a complete lineof recessed luminaires having trough shaped housings which may befabricated, with the exception of minor alterations dependent upon theparticular type of building construction in which such luminaires areemployed, from the same forming tools and which utilize the samecomponent parts.

Another more specfic object of this invention is to provide anovelreflector structure which may be removed and replaced in luminaireshaving a trough-shaped housing, from the open side of said housing inorder to facilitate repairs to the electrical components of suchluminaires without requiring the removal of any other comonent part.

Anothermore specific object of thisinvention is to provide a recessedtype luminaire having atrough-shaped housing member having a novelconstruction whereby the various components comprise an efficientreflecting surface.

These and other objects of this invention will become more apparent whentaken in conjunction with the attached drawings, in which:

Figure 1 is a perspective view of a luminaire installation having someparts broken away and shown in section, and other parts shown removedfrom the position which they normally occupy and illustrating atopposite sides two diiferent type of luminaire support members;

Fig. 2 is a perspectiveview partially in section and partly broken awayof aluminaire installation of a different type than that shown in Fig.l, for plaster or dry type ceiling or wall constructions, andillustrating one shielding device in an open position;

Fig. 3 is an exploded perspective view of an end of a body member of onetype of luminaire and the end plate therefor;

Fig. 4 is a cross-sectional view of one form of a luminaire body memberillustrating a center support;

Fig. 5 is an exploded perspective view of an end of a body member of atype of luminaire, different from that shown. in Fig. 3, and the endplate therefor;

Fig. 6 is an end view of the type of luminaire shown in Fig. 3 having anend plate positioned thereon with a portion broken away;

Fig. 7 is an exploded partial perspective view, partially in section,illustrating the method of joining two body members of adjacentluminaires; and

Fig. 8 is an exploded perspective view of a hanger bracket and themounting accessories utilized in sup porting luminaires.

In laying out a lighting system utilizing one or more types of recessedluminaires, the method of supporting the luminaires is a matter ofchoice dependent to a degree of the type of opening and the type ofceiling construction involved. This method of supporting such luminairesin various ceiling constructionshas, to a degree, become standardized.One particular generally adopted method of mounting such luminaires isillustrated in Fig. 1 and employs a snap-in locking member which may beof various standard designs. In general, however, all such snap-inlocking members are designed so that a standard form of locking flangeon the luminaire may be secured thereto. In Fig. 1, two differentsnap-in locking members are shown, one as standard T-bar 2, the other aninverted heart-shaped snap bar 4. T-bars 2 may be secured in place bysuitable means (not shown) and cross-braced, if desired, by any suitablestructural members such as channels 6. Snap bar 4, as illustrated, issupported by an adjustable hanger 8 which is suitably- 3 suspended froman upper cross framing or ceiling structure (not shown). A standardflange form may be secured in either T-bar 2 or snap bar 4, ordinarily,however, two T-bars 2 or two snap bars 4 would be utilized ratherthanone of each, as shown. T-bar 2 and snap bar 4 are each provided with alongtiudinal central bottom opening. T-bar 2 has downwardly extendingarms 10, each having an outwardly offset head 12 therein, which areadapted to be engaged by a standard flange shape inserted in the opening14 between arms 10. Snap bar 4 is provided with downwardly and outwardlysloping side members 15, each of which is terminated in an inwardlyrounded reversely bent portion 16. The bent edges 16- are adapted to beengaged both by the hanger 8 and by a standard flange shape inserted inthe opening 18 between bent end portions 16.

Asshown in Figs. 3 and 7, a luminaire incorporating the features of ourinvention comprises a trough-shaped body member 20 having downwardlyextending side walls 22 each of which has at its lower edge an irregularshaped light trap 21 and and upwardly extending flange 24 having anintegral rounded inwardly offset longitudinal bead 26 therein. Bead 26is one particular standard flange form which is insertable in eitheropening 14 or opening 18. Thus, opposite sides of the snap-in lockingmember are of identical form so that the body member may be secured inplace merely by pushing upwardly until the engagement of beads 26 with abead 12 or edge 16 occurs. It will also be noted that by suchconstruction, luminaries of different lengths may be installedend-toendand that the luminaires may be slidably moved longitudinally inthe support members, and that such luminaires are supported on each sidefor their entire length. Also an acoustic ceiling material 28 may alsobe snapped into either T-bar 2 or snap bar 4 (depending on which type isemployed) not utilized by flanges 24 of the luminaire, in order toprovide a ceiling flush with the bottom edge of the luminaire.

Another method of installing luminaires is illustrated in Fig. 2 whereina non-snap-in type of construction is illustrated. In order to support aceiling flush against the body member 20, such as a plaster ceiling ordry type ceiling 19, light traps 21 of body member 20 terminate (Fig. inflat flanges 30. The ceiling may be supported by a number of structuralcross members, which may be secured in position in any suitable manner.As shown, two diflerent types of support members are arranged inparallel lines. One such support member comprises a U-shaped channel 32and the other comprises a plaster frame side member 34. If desired, thesupport members may be cross-braced by channels 36 secured to channels32 by wire lashing 38. Similar cross bracing may be used with members 34and suitably secured thereto. A U-shaped hanger 40, channel-shaped insection (Fig. 8), is secured to each support member from which theluminaire is supported, and comprises two downward extending arms 42which terminate in a central outwardly curved portion 44. Each arm 42 isprovided with a series of spaced vertical holes 43 through which, by anysuitable means such as a bolt and nut assembly, a variety of tie clipsmay be secured. The selection of the particular tie clip is dependentupon the particular structural support member employed. When a channelsupport member such as channel 32 is employed, an L-shaped tie clip 33is used which is provided on one arm with two holes 50 which may bealigned with holes 43 in either arm 42 of hanger 40 and secured theretoby any suitable means. The other arm of L-shaped tie clip 33 is providedwith an elongated slot 52 which allows for attachment to wood furringceiling members if provided, or for wire lashing clip 33 to channel 32.The selection of the particular mating holes 43 in arms 42 with holes 50in clip 33 is dependent A assesa upon the size channel 32 or wood memberused as a support member.

With support members such as plaster frame side member 34, anirregular-shaped tie clip 56 is used. Curved end portion 44 of arm 42 ispositioned against the underside of the cross portion 68 of plasterframe side member 34 at one side of the member 34, and with the otherside of cross bar portion 68 of the plaster frame side member 34 engagedby the curved portion 66 of clip 56. As the back portion 58 of clip 56is provided with holes 60, the hanger 40 is clamped to the plaster framemember 34 by means of bolt assemblies 62 extending through holes 60 andmating holes 43 in an arm 42 of hanger 40.

The bight portion of hanger 40 is provided with threaded holes 72through which machine screws 74 extend, which are utilized with barrelnuts 76 for supporting a luminaire assembly. The bight portion 78 of thebody member 20 (Fig. 2) is provided with slots 80, only one of which is,shown, so that the body member 20 may be simply placed in position fromthe underside of hanger 40 so that machine screws 74 extend throughslots 80, and then be secured to hanger 40 by means of barrel nuts 76.As machine screws 74 cannot extend through barrel nuts 76, body member20 is secured in place by turning barrel nuts 76 clockwise by means of ascrewdriver inserted in their slots 77 so that machine screws 74 may bebacked outward from threaded holes 72 in hanger 40, until the flanges 30of the body member 20 engage the lower surface of the ceiling.

It will be noted that each side wall 22 of body member 20 comprises anupper portion 82 which is at approximately a right angle withthe bightportion 78 of body member 20, and an outwardly flared portion 84 whichis integrally connected either with a flange 24 or a flange 30 by theintegral irregular shaped light trap portion 21. Prior to installationof the body member 20, a U-shaped cross member 88, which may be formedfrom any suitable material such as sheet metal, is mounted in bodymember 20 at each end of body member 20, by any suitable means such assheet metal screws 89, extending through upper portion 82 of body member20 and threadedly engaging and extending through the upwardly extendingarms at each end of cross member 88. The cross member 88 is positionedat approximately the point where the portion 84 of each side wall 22starts to flare outward (Figs. 3 and 5).

Each U-shaped cross member 88 is provided (Figs. 3 and 5) with integralrectangular offsets 92 at the adjacent end of body member 20, in whichdownwardly extending lampholders 94 (Figs. 1 and 2) are positioned andwhich are secured to cross member 88 in any suitable manner. Lampholders94 are adapted to support fluorescent lamps 95, although the inventionis-not limited to any specific type of light source. Body member 20 canbe of various lengths and the position of cross members 88 andlampholders 94 may be varied in order that various lengths of lamps 95may be utilized.

A ballast unit 96 (Fig. 1) is installed, by any suitable means, such asa plurality of bolt and nut assemblies 98, upon the bight portion 78 ofthe body member 20. Once ballast 96 is installed, the requisite wiringof the luminaire may be accomplished and located in the chamber formedby the cross members 88 and the upper part of body member 20. A numberof standard knockouts (not shown) should be provided both in the upperportions 82 of side walls 22, and in the bight portion 78 of body member20, as may be needed. A reflector plate 100 is secured to the crossmembers 88 by suitable means, such as by the downwardly extendingmachine screws 102 which are threadedly engaged in cross members 88.Reflector plate 100 is provided with slots 104 at each of its ends whichare slightly greater in width than the diameter of machine screws 102 sothat either slot 104 of reflector plate 100 may be initially slid intoplace to receive the machine screw 102 at one end and a nut 105 placedthereon to hold one end of reflector plate 100 loosely in position. Bypositioning reflector plate 100 so that this screw 102 engages thebottom of one slot 104, the other end of reflector 100 will clear apreviously positioned screw 102 and nut 105 extending downward from thecross member 88 at the other end of body member 20. By then movingreflector plate 100 toward the other screw 102, both screws 102 can belocated at an intermediate position of the respective slots 104 and thereflector plate 100 secured to each cross member 88 by the nuts 105. Itwill be noted that exactly the reverse process can be followed inremoving reflector plate 100, so that the ballast 96 and the' wiringwill be accessible from the underside of body member 20, all withoutremoving the nuts 105.

The irregular-shaped light trap 21, which joins either flange 24 or 30with the lower portion 84 of each side wall 22 of body member 20,comprises an upwardly extending portion 106 from flange 24 or 30, ashort cross portion 108 at approximately right angles to upwardlyextending portion 106, and a downwardly sloping portion 107 joiningcross portion 108 with lower portion 84 in a plane below the plane ofcross portion 108. Each upwardly extending portion 106 is provided withspaced T-shaped slots 109 (Fig. 1) having stem portions in alignmentwith rectangular slots 111 in either flanges 24 or 30. Slots 109 and 111are provided so that a door assembly 110 or louver assembly 135 may beinstalled as a shielding device to control light passing through theopen bottom of the luminaire. As shown in Figs. 1 and 6, door assembly110 comprises a rectangular frame having side members 112 and endmembers 123 which may be removably secured together in any suitablemanner (not shown). Both side members 112 and end members 123 areprovided with integral upwardly extending flanges 117 at the outer edgethereof for the purpose of providing a continuous light trap cooperablewith light trap 21 of the body member 20. Side members 112 are alsoprovided with an integral channel 113 to support a glass or othertranslucent panel member 115 at its sides along its entire length.

As shown in Fig. 2, louver assembly 135 may comprise a frame havingchannel side members 114 and channel end members 125 which may besecured together in any suitable manner, such as by welding or brazing.Both side members 114 and end members 125 are provided with an integralupwardly extending flange 141 at their outer edges similar to flange 117of door assembly 110 whereby a continuous light trap is formed which iscooperable with light trap 21 of body member 20. Louver assembly 135comprises a plurality of spaced cross members 116 which are secured attheir ends to side members 114, in any suitable manner, such as weldingor brazing.

Door assembly 110 and louver assembly 135 are each provided with a pairof laterally extending stationary T-shaped hinges 118 which may beinserted into the slots 109 of light trap 21 at either side of the bodymember 20, whereby either door assembly 110 or louver assembly 135 maybe removably pivotally mounted to the flanges 24 or 30 by the stemportion of T-shaped hinges 118 extending through the narrow portion ofthe T slots 109 when closed, and through slots 111 when open. The sideframe members 112 and 114 are also provided with a pair of spacedT-shaped latches 120 on the side of the door assembly opposite fromT-shaped hinges 118. The latches 120 are adapted to engage the adjacentslots 109 when extended to latch door assembly 110 across the opening ofbody member 20. The method of supporting and latching door assembly 110and louver assembly 135 forms no part of this invention and is fullydescribed and claimed in the copending application of Nick Stuffer andLeonard H. Seeley on Luminaires, Serial No. 348,666, filed concurrentlywith this case and assigned 6 to the same assignee as this invention.For a more complete description of this feature, the above-identifiedapplication is referred to.

In order to close the open ends of the body members 20, each flaredportion 84 of side walls 22 is provided at its outer edges with arectangular notch 300 and with a slot 122 displaced inwardly from andapproximately parallel to notch 300. A hole 124 is provided betweennotch 300 and slot 122, and a slot 126 is provided in the bight portion78 of body member 20. As shown in Figs. 3 and 5, end cover 128 isprovided with an upwardly extending tab 130, and a tab 132 at each ofits sides having a laterally inwardly extending flat portion 134 with ahole 136 therein. Side tabs 132 are also provided with angular outwardlyextending triangular projections 138. End cover 128 may simply be placedin position by moving the end plate 128 upwardly so that extending tabis received in slot 126 and at the same time projections 138 enter slots122, until flat portions 134 rest flush against the inner side ofoutwardly flared portions 84 of side walls 22. Holes 124 and 136 arethen aligned and end cover 128 may be secured in place by any suitablemeans such as sheet metal screws, not shown, inserted through thesealigned openings. Fig. 6 illustrates in part such an end cover securedin place. If desired,

a U-shaped sheet metal nut 196 (Fig. 7) having an inner clearanceopening 302 in one of its legs in alignment with an opening 198 havinginwardly facing projections 301 in the other of its legs, may beinserted over lower portion 84 of each side wall 22 so that its bightportion engages the bottom of notch 300 and so that hole 124, opening198 and opening 302 are in alignment. As sheet metal nuts 196 areusually fabricated from a light gauge of sheet metal and are formed withtheir arms bent towards each other, a spring force is produced betweenthe arms which holds the nuts 196 on the side walls 22. With such anassembly, the inner leg of a nut 196 is positioned between the flaredportion 84 of a side wall 22 and flat portion 134 of an inserted endcover 128. A sheet metal screw having a cone shaped end, such as screw194 (Fig. 7), may then be manually inserted into sheet metal nut 196 andengage projections 301 and be supported thereby until the end cover 128is tightly secured (at each of its sides) to body member 20 bytightening screws 194. If desired, end cover 128 may be provided with astandard knockout 127 in order to facilitate the wiring of theluminaire. With the type of ceiling installation shown in Fig. 2, wherean outwardly extending flange 30 is required, an end flange member 142having an upright portion 144 with inwardly extending tabs 146 may besecured to and cover 128 by inserting tabs 146 in slots in end cover 128and bending tabs 146 backward against the inner surface of end cover128.

Body member 20 may be of varying lengths, however, in order toaccommodate the present day standard 8 foot lamp, additional problemsare encountered. One difficulty encountered is in providing a doorassembly 110 and louver assembly 135. In general, a single door of suchlength has not proven practical, therefore two shielding devices in atandem arrangement has been adopted. Such an arrangement entails aproblem of objectional light leakage between the shielding devices andthe luminaire, both along the sides and ends. Another difficultyencountered in long luminaires is that they have a tendency to bow andsag and therefore do not hold their shape over their entire length.Also, the reflector members 100 tend to sag downward objectionably. Inkeeping with the objects of our invention, We have provided a novelcenter support which overcomes the difliculties of long lengthluminaires.

Our novel center support means (Fig. 4) comprises an inverted U-shapedcross brace 150, which may be fabricated from any suitable material suchas sheet metal, and has its legs secured to upper portions 82 of eachside wall 22 of body member 20 by any suitable means, such as threadcutting screws 152. A reflector plate 154 which is'identical with thereflector plate 100, previously dis cussed, except that a central Vridge 155 is provided to increase its rigidity, is positioned againstthe underside of cross brace 151) and secured thereto by a machine screw156 extending through holes in cross brace 150 and V ridge 155, andwhich is threadedly engaged by a nut 158 bearing against the apex of theV ridge 155. If desired cross member 88 may also "be provided with a Vridge (not shown) to provide additional bracing for reflector plate 154.

The lower portion 84 of each side wall 22 of body member is crosssupported by means of an approximately channel-shaped brace 160 havingupwardly extending U-shaped tabs 162 at each end which are insertable inslots, not shown, in. light traps 21 of body member 20. Tabs 162 areprovided with extending ends 164 to position cross brace 160. withreference to body member 20 by engaging cross portion 108 of light trap21 of body member 20. The slots in light traps 21 of body member 20 aresuch that the arms of U-shaped tabs 162 are freely insertable into saidslots, and the brace 160 is biased to such position by a spring 168.Brace 160 is slidably and pivotally mounted at its mid-point in orderthat it may be removed from the slots in the light trap 21 and swung toa position approximately parallel with the lamps. This is accomplishedby providing a U- shaped bracket 172, which may be formed of anysuitable material such as sheet metal, and is removably secured toreflector 154 by means of machine screws and nut assemblies 174extending through integral tabs 176 of bracket 172, through reflectorplate 154 and through slots (not hown) in brace 150 which extend to oneside edge of brace 150. The lower cross portion 17? of bracket 172 isprovided with a hole through which a stud 166 extends which is securedto cross brace 16%! by any suitable means such as Welding or brazing. Acoil compression spring 168 is provided upon stud 166 and it engages theupper surface 167 of the cross portion 178 of bracket 172 and is heldcompressed by any suitable means, such as the nut 170 threadedlyengaging stud 166. If desired nut 17% may be secured to stud 166 in anysuitable manner, such as by staking, so that it cannot be removed byhand.

In operation, cross brace 166 is pulled downward thereby compressingspring 16?: so that a suflicient clearance is provided to permit removalof tabs 162 of cross brace 160 from slots in light traps 21 of bodymember 20. Thereafter brace 160 may be freely rotated and then releasedand held in any desired released position by means of the spring 1%.After such a luminaire has once been relamped, the reverse process isfollowed. it will also be noted that as screw and nut assemblies 174 arepositioned within slots in brace 150, cross brace 16% may be completelyremoved along with the reflector 154 by merely loosening assemblies 174and moving reflector 154 endwise until assemblies 174 clear the slots inbrace 150.

As shown in Fig. 2, applicants have provided an upper tie plate 181]which may be removably secured to each bight portion 78 of body member20 of each of two adjacent luminaires by means of a plurality of boltand nut assemblies 132. The lower portion of each luminaire is fixedlypositioned with reference to each other by means of a novel connector184 (Fig. 7) which is provided with means to engage slots 122 in thelower portions 84 of each side wall 22 of the two adjoining body members21) at each side of connector 184. Connector 1E4 comprises an invertedU-shaped cross bar portion 186 having at each of its ends an integralangular upwardly extending portion 188 each of which is provided at eachof its sides with a triangular projection 192 which are at exact rightangles to portion 188. When the connector 184 is placed in position fromthe underside of body member 20, the angular portions 188 then restflush against the inner legs of the nuts 196 which have previously beenpositioned in notch 3119 of body member 20 so that their openings are inalignment with hole 124 of lower portions 84, and so that triangularprojections 192 enter slots 122. Each angular portion 188 is alsoprovided with two slots 1% so that when connector 184 is inserted fromthe bottom of the body members 2t and tabs 192 engage slots 122 in thelower portions 34 of side walls 22 of body members 20, slots 190 are inalignment with holes 124 in lower portions 84 of each side wall 22 ofeach body member 20. Connector 184 may then be remov ably secured toeach body member 20 by any suitable means such as pointed sheet metalscrews 19d extending through slots 1% through the openings 124 in sidewalls 22 of each body member 20, and engaging U-shaped speed nuts 1%. Itwill also be noted that the engagement of triangular projections 192 ofconnector 184 with slots 122 of each side of adjacent body members '20forces lower portions 84 of adjacent body members in their correctposition.

Luminaires constructed in accordance with our invention eliminateobjectionable light leakage between the shielding devices 110 and 135and the body member 20, and, depending upon the particular construction,end covers 128, connectors 184 or cross braces 160. Since the flanges117 of door frame 112 are located outwardly of the lower edges ofportions 84 of the housing side walls and beneath light trap portions108, no direct light is directly observable from below. Any lightstriking the horizontal portion of the side member of the frame 112 willbe reflected upward toward flange 117 which in turn will reflect thelight inwardly back into the body member 20. Similarly any direct lightrays striking flange 117 will be reflected back into the body member 20.The direct light rays from lamps 95, as well as the reflected light raysfrom lower portions 84 of side walls 22, cross member 88, reflectorplates or 154, which are all reflecting surfaces, which enter the space123 are first reflected from the inner surface of frame 112. if desired,the inner surface of frame 112 may be finished with a light absorbingblack paint in order that most of the incident light would be absorbed.The remainder of the light rays which are reflected through light trap21 of body member 20 are dissipated by multiple reflections betweenflange 117 of door assembly and the upright portion 106 of the lighttrap 21. Thus, any light passing through the opening between channels113 and portions $4 will be so reflected by flange 117 that no directlight leakage will occur to the exterior. The construction of flange 141of louver assembly is substantially identical with flange 117 of doorassembly 110 so that objectionable light leakage will be prevented withthe louvered type construction. End covers 128 (Figs. 3 to 5) areprovided with inward light trap offsets 129 at their lower edges inwhich either flange 117 or 141, dependent upon whether door assembly 110or louver assembly 135 is installed, may be positioned in overlappingrclationship with offset 129 so that no objectionable light leakage willoccur between door assembly 110 or louver assembly 135 and end members128, in the same manner as previously discussed. In a similar mannercross brace 161i and connector 184 are provided with downwardlyextending arms'131 and 133, respectively, between which flanges 117 or141 of two adjacent door assemblies 111) or louver assemblies 135 may bepositioned. It is thus apparent that light trapping provisions are madefor all four sides of the two types of doors illustrated, whether only asingle door is employed, or a plurality of doors are arranged end toend.

Thus, it will be observed that we have a novel basic luminaire which isreadily adapted to be utilized in a variety of diflerent lightinginstallations. Primarily, as the body members utilized with diiferentmethods of support are identical with the exception of the outermostflanges, the same basic methods of fabricating and the same componentparts may be used. It is obvious that such an arrangement results insubstantially lower production costs. Further, it will be noted that ourluminaires are readily adapted to be installed and easily serviced fromthe underside of the luminaire without tools or loose parts resulting insubstantial installation savings over the method of installing presentlyemployed. It will also be more particularly noted that the lowerportions of the body members, the reflector and the cross plates allfunctionas light reflecting surfaces. During installation, both theconnectors and the end plates hold the contour of the body memberthereby insuring that all the body members are in alignment. Inservicing, the factthat all parts of the luminaire including the wiringand the ballast unit thereof are accessible from the underside resultsin a substantial reduction in servicing cost. It will also be noted thatalthough our luminaires result in substantial savings to the purchaserthat such savings are accompanied by a superior luminaire. Thus, theinterchangeability of parts which permits a luminaire to be used alone,in pairs, or in a line or lines, results in a lighting system which mayreadily be altered if desired, due to future lighting requirements.

Although we have shown and described one particular line of luminaireswhich incorporate the various features of our invention, in accordancewith the patent statutes, we are aware that other modifications mayeasily be made without departing from the spirit of our invention.

We claim as our invention:

1. A luminaire including an open ended trough shaped body member havingdownwardly extending side walls, means secured to said body member forsupporting lamp holding means between said side walls, a lower crossbrace rotatably located below said lamp holding means and mounted formovement on said body member between said side walls, said brace havingextending arms at each of its ends engageable with apertures in each ofsaid side walls upon upward movement of said brace, spring means forbiasing said brace upwardly, said spring means being compressible topermit said brace to be withdrawn from engagement with said aperturesand rotated between said side walls.

2. A luminaire comprising an open ended trough shaped body member havingdownwardly and outwardly extending side walls, means for supporting lampholding means between said side walls, at least one covering meansspanning one end of said body member to close said one end of said bodymember, said covering means being located between said side walls atsaid one end and having integral tabs at each of its sides which extendinwardly along and in engagement with the inner surface of said sidewalls, each of said tabs having an integral angularly outwardlyextending projection thereon at its free end, each of said side wallshaving an aperture therein at each of its ends through which one of saidprojections extend, and means for securing said tabs to said side walls.

3. A lighting system comprising, two inverted trough shaped luminariesmounted end-to-end, a connector adapted to be inserted from theunderside of said luminaires at the juncture of said luminaires betweenthe side walls thereof to a position where it spans said side wallsadjacent the free ends thereof at said juncture, an integral plate ateach end of said connector extending angularly upwardly relative to saidconnector so that said plates are positioned against the lower portionsof the inner sides said body members for supporting lamp holding meansbetween the side walls thereof, each of said side walls having anaperture adjacent its abutting end and at the lower edge thereof, aconnector spanningsaid side walls at their abutting ends and locatedbelow said lamp holding means and comprising an inverted channel shapedmember, a plate secured at each end of said channel in an angularrelationship therewith, each of said plates spanning the abutting endsof said side walls and having integral projecting means engaging saidapertures in the adjacent side walls of said body members: to hold saidbody members in abutting relationship, and means for removably securingsaid plates to said side walls.

5. A luminaire comprising an inverted trough shaped body member, meanssecured to said body member for supporting lamp holding means betweenthe side walls thereof, each of said side walls being provided at eachof its ends near its lower edge with a slot in juxtaposition with afirst opening but spaced therefrom the same predetermined distance asthe other juxtaposed openings and slots, a cover on one end of said bodymember having inwardly extending tabs at each of its sides engaging theinner surfaces of said side walls and having a second opening therein,said tabs having integral outwardly ex.- tending ends received withinopposed ones of said slots and spaced from said second openings in theaforesaid predetermined distance whereby said first and second openingsare aligned, means cooperable with said first and second openings forsecuring said cover to each of said side walls, a connector spanning thelower ends of said side walls at the other end of said luminaire andhaving an upwardly extending portion at each of its ends at least partof which engages the inner surface of said side walls to connect theother end of said bodymember with another similar body member, each ofsaid extending portions having spaced outwardly extending portions oneof which is secured in the adjacent slot and the other of which islocated outwardly of said other end of the luminaire.

6. A lighting system comprising two inverted trough shaped luminairessupported in tandem so that adjacent ends abut each other, the sidewalls of said luminaires diverging, an opening in each side wall of eachluminaire adjacent both its abutting end and its free side edges, anelongated connector spanning the free ends of the side walls of saidluminaires at their abutting ends and having an integral plate at eachof its ends which extend generally upwardly and spans the abuttingadjacent side walls of said luminaire, spaced tabs on each of saidplates extending outwardly therefrom, and said tabs being received insaid openings in adjacent side walls so that said connector may beinserted from the open side of said housing with said plates engagingthe inner surface of said side walls, and means for removably se curingsaid plates to said side walls.

7. A luminaire including an open ended inverted trough shaped bodymember, means secured to said body member for supporting lamp holdingmeans between the side walls thereof, a lower inverted channel shapedcross brace located below said lamp holding means and mounted at anintermediate point on said body member between said side walls forsubstantially vertical sliding movement toward and away from the bightportion of said body member and for pivotal move ment from a positionwhere it extends transversely of and spans the sides of said body memberto a position substantially parallel to said sides of the body member,said brace having upwardly extending arms at each of its endsautomatically engageable in apertures in divergent portions of each ofsaid side walls upon upward movement of said brace to locate said bracein operative position at the free edges of said side walls of the bodymember, and spring means for biasing said brace upwardly to itsoperative position. v

8. A luminaire including an open ended inverted trough shaped bodymember, means secured to said body member for supporting lamp holdingmeans between the side walls thereof, a lower cross brace located belowsaidlamp holding means and mounted at an intermediate point on said bodymember between said side walls for substantially vertical slidingmovement toward and away from the bight portion of said body member andfor pivotal movement from a position where it extends transversely ofand spans the sides of said body member to a position substantiallyparallel to said sides of the body member, said brace having upwardlyextending arms at each of its ends automatically engageable in aperturesin divergent portions of each of said side walls upon upward movement ofsaid brace, and spring means for biasing said brace upwardly to itsoperative position.

References Cited in the file of this patent UNITED STATES PATENTS

